The present invention relates generally to an apparatus for surveying physical features of highways and, in particular, to an apparatus for generating a data base of information for use in traffic engineering matters.
An accurate inventory of the location and condition of various physical features of highways is essential to the efficient maintenance of our state and federal highway systems. U.S. Pat. No. 3,796,864 discloses a vehicle separation measuring system in which distance pulses generated in a lead vehicle are transmitted by radio to a tracking vehicle and are compared with distance pulses generated by the tracking vehicle to generate an audio output corresponding to a comparison of the actual distance between the vehicles with a desired distance between vehicles. U.S. Pat. No. 3,809,864 discloses a paint sprayer marking system and an associated distance measuring instrument is described in U.S. Pat. No. 3,865,305.
The following U.S. patents show systems for displaying the position of the vehicle relative to mile marker posts: U.S. Pat. Nos. 4,068,307; 4,103,332; 4,145,605; and 4,229,724. The following U.S. patents show electronic circuits which are utilized as vehicle trip odometers: U.S. Pat. No. 4,263,657; 4,382,178 and 4,665,497. U.S. Pat. No. 4,470,149 discloses a circuit for measuring the length and counting road marking line segments as they are painted.